definitely wordpress.orgbut u need to do some tweaks like installing 2-3 plugins and chnage permalink structure using WP....... wordpress is best....
Drupal is a CMS but has a blog feature out of the box. With a few additional modules, Drupal sites can rank really well.
Drupal is best to get good ranking in search engines. If you use its categories modules properly, your content will be crawled from many pages according to the tags selected for the content. So I think you should use Drupal, its far better then wordpress.
drupal is a cms (content management system) http://drupal.org/ I also need a simpler search engine friendly blog system.Both wordpress and drupal is complex for me.
If you want to get some help/services about Drupal (Open source integration and modification) please PM me. I have good experience maintaining Drupal based websites as I have already worked on 2 websites.